Respirator



I N VEN TOR.

R. MALcoM Oct. 13, 1931.

RESPIRATOR Filed Nov. 50, 1928 Patented ct. 13, 1931'v Ularriznxv .STATES aszaoza AowlcF.

ROBERT MALoolvr, or CHICAGO, IrinINoI'sf nnsrrnaron Application mea November 3o, i928. sena1'No-3lzacss.

These improvements relate to inhalation devices usually vcalled respirators, with speciiic'relation to the exhaust means,usually called the exhaust valve, therefor.

the nose, mouth, throat and lungs from the effects of dangerous atmospheres, for example such as contain dust, poisonous gases or fumes.y It is immaterial to the present lo invention what the particular type, form or general kind of the respirator maybe sincer :20 reliably close, asan automatically-operating valve, on the inspiration of air by the user while permitting the desired free expiration of lung contents therethrough.

In the drawings Figure 1 shows a well# .13.55.25 known type or form of respirator having these improvements applied thereto and shown partly in section, parts of the mask ,body being also broken away g YF ig. 2 is an edge view of the exhaust device P0 on a largerscale as it appears before application to the mask Fig; 3 is a side view of the exhaust device as applied to the mask, the same being broken away and with a fragment of the mask body .z if? .f5 sectionallyshown Fig. 4 is a section showing the structures of Fig. 3 on the line il-4 thereof; and

F ig. 5 showsthedevice invedge view as it `appears upon an exhalation4 from the lungs. i The valve or exhaust devicebody 10 is of soft, thin, flexible rubber, and is formed as a tube, but with'the sides `10a and 10bthereof lying face to face andflat, one upon the'o'ther.

It is vulcanized in the flat shape shown by f4.5 Fig. 2, and its tendency is therefore toreturn to that shape when distencled by air pressure within. stantially long strip form and cut to the short lengths desired, these lengths being open at each 6nd.

Such respirators are designed to prote'ct proved way and which will effectively andV Ther material may 4be made in sub-,

r'have expanded outward yunderthe#effects of the exhalation and how the openings .16 then .lead-directly into the lhollow interior. f 100 the pastit hasb'een the practice to take i a piece or length of such fiat rubber tubing ope-nat bot-h v-en'dsand apply one Yopen end v upon a nipple as j12 issuing from the body of .'thefmask, the rubber piece 4being held thereon' 65 as' by atwisted wire 13. In the `older practice ust described 4thesides `of therubber struc- `ture would spreadA apart on the 4exhalati'on kand open --at Ythe-normallyl lower' or free end thereof, permitting the lung contents to, 6G escape.` On the ensuing ,inhalation depend?Y i encewas had upon the tendency ofthe rubberV to proyide'such ksubstantial closeness of .the

two sides as" 10a and 10b to eachother as `would prcvent-thefintake vof air 'at l,the free 55 end.V The 'results have not been-satisfactory,

.liowefver, especially after considerableuse of kthedevlceand also :after the passage of time.

Repeated use hascaused the rubber to `become flabby and distended at the' free endf-portion, 70

while time operates to -lesserrtheelasticityy of the. rubber, permitting an openpermanent set to developg. ,1 l

AThe present'improvements ythus include as Y its body :structure much in quantity that is75 old and well-known.' yOne .-novel feature hereinshown is the. clamping .and closing yelement A14 at thebottom of the Ybody* 10 ex tending laterally Y from edge tov edgel thereof, the same conveniently beingan the yform ofY 0 sheet metal, saytin plate, fol'dedsubstantiali 'ly U-shaped in cross view, encompassing the Vlower and open ec ge A 'Jortions ofthe-body, the

clip 414 beingpressed tightlyk thereupon and securedthereto vasby the indentations 15 in.,,5 themetal j i The 411M-1t featuronerelty and illportance fis the provisionof preferably a pair of openings 1 6;at the edge portions 10a' and'openingV into the hollow interior lwhen such 3 hollow Q0 interior occurs, namelyron an 'explration,

these holes 16 being formed by simplycutting v A through,both layers ofthe rubber material at the sealedmarginal edges 10c thereof.

IThe exhaust air escapes through these-95 Y KVVopen-ings 16', -as is-readily to beiobserved from Fig.' -showing how. the ysidesof.the body 10 i I may have auxiliary openings, as 17, should it be desired to provide for further convenience of air escape; but in actual practice, in a mask of the kind illustrated, the openings 16 have ample capacity.

By holding the lower ends of the body together, which may be done by other means than the clip illustrated, the tendency of the body to change its desired flat condition with the sides lying flat, one upon the other, is greatly reduced if not entirely overcome. The flexibility of the rubber to permit exhaust is not interfered with. When the inspiration takes place and suction occurs at the openings as 16 or 17 the sides as 10a: and 10b return to flat-lying position not only through the natural tendency of the parts to regain the shape in which they were vulcanized, but this tendency is increased by the fact that the expansion, as shown by Fig. 5, is against resistance offered by the clamping element 111, so that the return to normal condition is by virtue of an added factor. In the older construction the turned-over edges at 10c were the factors chiefly making for a return to flat form, while according to the present invention there is a third factor, acting similarly, and with even added effect.

This added eect arises, for one thing, from the fact that the body 10 is held to its full normal width at the bottom. rlhe edges 100 may not approach each other there; and the influence of this extends upward into the rubber body. The tendency of the body to become narrower is therefore greatly reduced, and, conversely, its tendency to retain its flat shape is greatly increased.

Advantageous results according to these improvements may be had by vulcanizing or otherwise sealing the lower end of the valve body, but substantially the construction shown is preferred. The bottom may have other shapes. The relative position of the vents, as 16 or 17 is not particularly critical, but they should be in the lower general area. Their positions as illustrated are entirely satisfactory in the structure shown.

In the original Vdrawings submitted here-- with the illustrations of Figs. 2, 3, 4 and 5 are substantially to scale.

l contemplate as Vbeing included in these improvements all such changes, variations and departures from what is thus specifically illustrated and described as fall within the scope of the appended claim.

l claim:

A respirator exhaust valve of the character described comprising a piece of thin, soft and flexible material in tubular form with its sides lying face to face one upon the other, one end of said piece being open and adapted to be secured operatively to the respirator body and the other end thereof having a substantially stiff clip compressed thereon and holding the sides together substantially from ROBERT MALCOM.

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